212 MORPHOLOGY AND EVOLUTION bsemorrhoidal vessels below; it supplies the descending and iliac colons. In the Chimpanzee the superior liaemorrhoidal artery (S.H.A.) goes down into the pelvis to supply the rectum and anus; it is relatively larger than in Man, and replaces part of the hgemorrhoidal distribution of the internal iliac artery. The branches of the mesenteric arteries in the Gibbon differ from the above, Kohlbriigge (199) points out that the ileo-colic branch of the superior mesenteric artery supplies the ascending colon, and there is no right colic artery. The middle colic artery also arises from the superior mesenteric artery, and supplies the ascending and transverse colons. The inferior mesenteric artery supplies the descending colon and rectum. In the Orang the middle colic artery comes from the superior mesenteric trunk. The common iliac arteries are similar in the Apes and Man. The external iliac arteries course as in Man. In the Chimpanzee they may give off no branches at all, but sometimes the deep epigastric arteries arise from them. Eisler (442) points out that they give off the deep epigastric, spermatic, and deep circumflex iliac arteries in the Gorilla. The internal iliac artery (fig. 44, E) in the Chimpanzee divides into anterior and posterior divisions, whose branches are as follows:— A.—Anterior Division, ' Uteri-vaginal ves- (1) A trunk which divides into, a sejs. Superior vesical artery (S.V.A.).